Lyrognathus lessunda, West, Rick C. & Nunn, Steven C., 2010

West, Rick C. & Nunn, Steven C., 2010, A taxonomic revision of the tarantula spider genus Lyrognathus Pocock 1895 (Araneae, Theraphosidae), with notes on the Selenocosmiinae, Zootaxa 2362, pp. 1-43 : 25-31

Lyrognathus lessunda sp. nov.

( Figs 63–83 , 114 )

Types: female holotype, 1 female, 3 male paratypes, S74067, S74066, S74070 , S74068 and S74069 , respectively, Lombok Island (8°08' S, 117°24' E), Lesser Sunda Islands, Indonesia, col. B. Sutrino, 15 Aug. 2002, QM.—examined.

Etymology: The specific name is a contraction of Lesser Sunda Islands in the Malay Archipelago of Indonesia and, therefore, a noun in apposition.

Diagnosis: Differs from all other Lyrognathus species in the apically swollen “mushroom cap” that form bilobular spermathecae, present on both lateral and medial lobes in females and undivided scopula on tar. IV. Differs from L. crotalus in intercheliceral pegs (not spines), bilobular spermathecae and retrolateral basomedial cheliceral spines. Lyrognathus lessunda sp. nov. resembles L. achilles sp. nov., L. fuscus sp. nov. and L. robustus in having intercheliceral pegs (females and males) in combination with bilobular spermathecae and retrolateral basomedial cheliceral spines. Differs from L. achilles sp. nov. and L. fuscus sp.

nov. in the apical “mushroom cap” form medial lobes of spermathecae. Differs from L. robustus in the undivided metatarsi IV scopula for the full length ventrally and the absence of a third claw on tarsi IV. Differs from L. saltator in the undivided tarsi IV scopula, intercheliceral pegs and retrolateral basomedial cheliceral spines.

Description: Female holotype (in life, Fig. 63 ) with body length: 32.91.

Color (in life): intermolt and premolt entirely reddish brown/rust, postmolt dark brown posteriorly, shading to rust orange anteriorly.

Carapace ( Fig. 64 ): length 13.3, width 11.7 (width of anterior edge 8.7). Fovea 2.15, procurved, deep, slightly wider than OT ( Fig. 21 ). Carapace with 4 discernible hair types: 4 distinct types noted (C1 to C4): type C1, long, needle-form pallids border carapace entirely (darker basally): type C2, short blunt tipped, basally dark gray to distally pallid, cover entire carapace evenly, but reasonably sparse: type C3, short, thin wavy pallids, form basis of carapace mat: type C4, emerge from bothria-like collars, long, distally spiniform, pallid, lie in uniform arrangement of (>4) along anterior edge of each radial groove, (>4) along anterior edge of each thoracic groove, (>6) along anterior edge of each sulcal groove, (>8) along anterior edge of each caput groove and line of>4 along medial caput ridge (between OT and fovea).>4 more located behind each side of OT, nearest median caput row.

Eyes ( Fig. 65 ): ocular tubercle; length 2.0, width 2.35. Anterior row transverse. Posterior row slightly recurved. Eyes: AME, ALE, PLE = PME. OT hairs:>12 (C2) directly posterior to AME’s, 4 to 5 between PME and center of OT (directly behind each AME). 18 (C2) along median anterior OT surface. OT entirely covered in small, weak, pallid setae (C3), point to center of OT, posteriorly and anteriorly. Lateral small pallids sparse with no uniform direction/random arrangment.

Chelicerae ( Figs 77–80 ): length 4.0, width at base of each lobe 2.85. Ectal lyrate region a series of strikers (>50) up to 7 horizontal rows ( Fig. 79 ). Strongest and longest strikers on lowest rows. Each striker blade/ scimitar shape, with some filiform ends. Teeth, 14,>25 basomesal teeth. Intercheliceral pegs (>16 larger,>23 smaller) in tight cluster on basodorsal surface ( Fig. 78 ). Retrolaterally basomedially, with small cluster of short strong spines (>3), point distad ( Fig. 80 ). Antero-dorsally to retrolateral spines: patch of fine setae, dark, of medium length, blends into typical thicker pallid cheliceral setae. Setae filiform, seem to emerge from hemispherical bases.

Maxillae ( Figs 66 , 75 ): prolaterally plano–convex, anterior lobe well pronounced, many cuspules (> 120) on inner basoventral surface. Ventrally, diagonal to anterior lobe, basal projection evident, overly large, setose. Lyra ( Figs 75, 76 ): many bacilliform rods (>180) form dense, ovoid patch medially on prolateral surface, lowest row up to>20 bacillae longest rods in center of lowest row. Rods distally paddle-shaped with short to medium length shafts, largest with distal blades. At highest point, lyrate patch is>11 rows deep with smallest rods dorsally. Posterior end of patch truncate, anterior end slightly pointed distad/rounded. Immediately above the suture 10 to 15 small spines on anterior margin in disordered rows. Labium ( Fig. 67 ): length 1.75, width 2.4. Many small cuspules (>350) along anterior 1/3 surface. Labium with 2 discernible hair types (L1, L2); type L1: long, reasonably dark spiniform, curving distally toward anterior, most concentrated along lateral borders. Setae longest along anterior edge (>30); type L2, 1/2 length of L1, interspersed with L1 but more needle-form.

Sternum ( Fig. 66 ): length 7.25, width 6.2. Slightly wider posteriorly than anteriorly with 5 discernible hair types (S1 to S5): type S1, longest, thick blunt-tipped, darker basally, become pallid distally, entire cover, but sparse: type S2, elongate spiniforms, dark basally, distally pallid, on borders, most concentrated posteriorly: type S3, short spiniforms, overall sparse: type S4 short, thin pallids, form basis of mat: type S5 dark basally, but apically pallid, short blunt tipped, entirecover in sparse unorganised arrangement. Posteriorly between left/right cox. IV, border greatly acuminate, lateral sternal points also acuminate. Sigilla: 3 pairs, posterior, very large, ovoid, 1.7 lengths apart, 0.6 to 0.95 of their length from margin. Median pair 1/2 size of posterior, similar, 0.2–0.1 of their length from margin. Anterior pair somewhat obscured, on margin. Labio-sternal sigilla small, thin, but wide.

Legs. Setation: retrolateral surfaces of pat., tib., met. and tar. IV with distinct thick brushes of hair-like setae ( Fig. 71 ), penicillate. Legs: formula; (length) IV, I, II, III, (width) IV, III, I, II. Leg RF ~ 87.92. Leg lengths (fem., pat., tib., met., tar., total): holotype S74067: palp: 7.2, 4.3, 4.65, 0.00, 5.15, 21.3. I: 10.4, 6.15, 7.25, 6.3, 4.1, 34.2. II: 8.1, 5.2, 5.2, 5.25, 4.15, 27.9. III: 8.9, 4.8, 4.8, 5.6, 4.05, 28.15. IV: 10.65, 5.85, 8.25, 9.3, 4.85, 38.9. Paratype S74070 : palp: 7.3, 5.15, 5.2, 0.00, 5.25, 22.9. I: 10.25, 6.7, 8.0, 7.3, 4.65, 36.9. II: 8.55, 5.9, 6.2, 6.3, 4.4, 31.35. III: 7.75, 5.25, 6.7, 6.45, 4.15, 30.3. IV: 10.3, 5.95, 9.05, 9.80, 5.35, 40.35. Leg mid-widths (fem., pat., tib., met., tar., total.): (holotype only): palp: 1.85, 2.13, 1.71, 0.00, 2.05, 7.74. I: 2.45, 2.51, 2.63, 2.1, 2.15, 11.84. II: 2.35, 2.35, 2.12, 1.95, 1.75, 10.52. III: 3.15, 2.55, 2.35, 1.95, 1.85, 11.85. IV: 2.45, 2.83, 3.02, 2.35, 2.15, 12.8.

Scopula: undivided, for full length of met./tar. on all legs.

Coxae: some small black thorns prolatero-dorsally, no thorns retrolaterally on I–IV; easily seen dorsally; I longest, about 1.6 times length of II. IV widest, as long as III, basally rectangular with rounded corners; with ventral thorns prolaterally on I–IV. I–III ventrally with many long thick blunt setae proximally, pallid. No short black setae. IV with mixture of long thick blunt setae proximally, pallid intermixed with shorter thin pallid setae. Ventral surface of I–IV gently sloping anteriorly. Retrolateral setation: I–III with median narrow light brush, IV completely cover of light setae. I–IV retrolaterally lack ventral ledge. Ventral measurements for coxae (holotype only): I–length 6.8, width 3.1; II–5.8, 2.9; III–5.1, 2.8; IV–6.1, 3.4. Trochantera: I–length 2.6, width 2.7; II–2.6, 2.1; III–2.6, 2.8; IV–3.3, 3.1.

Trichobothria: on all tar., basal filiform field slightly wider than clavate field, merging evenly. Clavates on tar. I only in distal 1/2, long filiforms only in basal 1/2, shorter filiforms intermixed with clavates distally. Clavate extent on II–IV cf. I, only in distal 1/2. Shorter filiforms for length. Short epitrichobothrial field ( Raven 2005) on I shorter than clavates, uniform height for length. Tarsal organ not evident on legs I–IV.

Spines: met. I with 1 DV, met. II with 1 DV, 1 DPV, 1 DRV, met. III with 2 DV, 1 DPV, 1 DRV, 1 DD and met. IV with 2 DV, 1 DPV, 1 DRV, 1 DD, 1 DPL.

Claws: unarmed paired claws on all legs. No reduced third claw on leg IV.

Abdomen ( Figs 69 , 71 ): ovular, elongate, reddish brown; with 4 discernible hair types (A1 to A4): dorsally with 3 hair types: type A1, long, dark blunt-tipped, uniform color: type A2, mid-length, also dark, but distally spiniform, unlike type A1: type A3, form dense mat, mid-length, uniformly dark, needle-form (some stand erect, some run posteriorly but with similar morphology). Longest hairs (type A1) more concentrated posteriorly toward spinnerets, point distad, but proximally, hairs stand erect, medially curved (toward posterior). Ventral hair types almost same as dorsal, but type A2 and A3 more dense entirely. Type A4 hair, in very dense patch, trapezoidal, posterior of pedicel between median regions of cox. IV. Hairs of medium length, straight, pallid. Between anterior pair of booklungs, setal mat similar to rest of venter.

Genitalia ( Fig. 70 ): epigastric fold 4.95. Spermathecae bilobular. Lobes apically swollen with lateral lobes 2/3 length of medials. Medial lobes very long. Epigastric fold extends ca. 2/3 length of medial spermathecal lobes.

Spinnerets: PMS: length 1.45, width (medially) 0.65. PLS: section lengths; basal 2.85, medial 1.30, apical 2.10. PLS section widths (medially); basal 1.32, medial 0.98, apical 0.67; with 2 discernible hair types (SP1, SP2): SP1 very short and distally blunt pallid, covers both pairs ventrally; second form (SP2), very similar but up to twice as long, dorsally on all segments.

Male paratype ( Fig. 81 , as in female except) with body length: 30.28. Color (in life): reddish brown with slight purple sheen in natural light. Carapace ( Fig. 84 ): length 11.9, width 9.35 (width across anterior edge 6.9). Fovea 1.75 wide, deep, procurved.

Eyes ( Fig. 83 ): ocular tubercle; length 1.86, width 2.17. Anterior row transverse. Posterior row slightly recurved. Eyes, largest to smallest: AME, ALE, PLE, PME.

Chelicerae ( Fig. 86 ): length 3.9, width at base of each lobe 2.5. Teeth,12,>15 smaller basomesals. Intercheliceral pegs (>9 larger,>15 smaller) in tight cluster on basodorsal surface ( Fig. 85 ).

Maxillae ( Fig. 87 ): anterior lobe well pronounced with many cuspules (>140) on inner basoventral surface. Lyra ( Fig. 87 ): immediately above suture 10–15 elongated spines medially to anterior margin. Bacillate rods relatively slightly shorter than in female. Labium ( Fig. 84 ): length 1.95, width 2.65. Many small cuspules (>300) along anterior 1/4 surface.

Sternum ( Fig. 84 ): length 5.85, width 5.05. Wider posteriorly than anteriorly, with thin but even cover of short setae, interspersed with many longer darker setae. No spines around edges. Lateral points acuminate, but not posterior angle.

Legs: formula; (length) IV, I, II, III; (width) III, IV, I, II. Leg RF ~97.07 ( S74069 ). Lengths (fem., pat., tib., met., tar., total): paratype S74069 : palp: 7.25, 4.7, 6.9, 0.00, 2.4, 21.25. I: 11.4, 6.7, 9.4, 8.45, 5.45, 41.4. II: 10.4, 5.5, 8.15, 7.45, 4.6, 36.1. III: 8.55, 5.3, 5.5, 6.75, 4.15, 30.25. IV: 11.85, 5.8, 9.35, 10.85, 4.8, 42.65. paratype S74068: palp: 6.9, 4.75, 6.35, 0.00, 2.35, 20.35. I: 11.1, 6.15, 9.45, 8.1, 5.15, 39.95. II: 9.05, 5.35, 7.2, 7.25, 5.05, 33.9. III: 8.0, 4.85, 5.35, 6.85, 3.95, 29.0. IV: 11.25, 5.55, 9.25, 11.45, 4.75, 42.25. paratype S74066: palp: 8.6, 5.0, 7.1, 0.00, 2.45, 23.15. I: 12.15, 6.75, 10.6, 9.15, 5.9, 44.55. II: 10.0, 5.75, 8.05, 8.15, 5.25, 37.2. III: 8.45, 5.3, 5.65, 7.85, 4.25, 31.5. IV: 12.25, 5.65, 10.25, 12.65, 5.15, 49.15. Leg mid-widths (fem., pat., tib., met., tar., total.): paratype S74069 : palp: 1.85,1.95, 1.9, 0.00, 2.03, 7.73. I: 2.26, 2.45, 1.98, 1.47, 1.35, 9.51. II: 2.25, 2.17, 1.95, 1.37, 1.27, 9.01. III: 3.15, 2.3, 2.1, 1.37, 1.51, 10.43. IV: 2.35, 2.37, 2.27, 1.52, 1.36, 9.87. Leg IV with reduced retrolateral setal brush, most concentrated on retrolateral metatarsal surface, proximally, but on tib. ( Fig. 81 ). Coxae ventral measurements ( S74069 ): palp–length 5.97, width 2.66; I–5.52, 2.87; II–4.69, 2.67; III–4.2, 2.73; IV–5.44, 3.2. Trochantera: palp–length 2.31, width 1.87; I– 3.36, 2.78; II–3.04, 2.69; III–2.34, 2.7; IV–2.96, 2.86.

Claws: as in female, except on apical ventral region of paired claws of IV, 2–3 small teeth.

Genitalia. Palp ( Figs 88–90 ): tib. mildly incrassate, tapers distally. Cymbium bipartite, tegulum large. Lanceolate embolus slightly tapers distally with very little flaring, proximally emerges anterior to tegulum. Relative length of palpal tibia ca. twice length of embolus. Longitudinal keel distinct (embolus not terete), runs entire length of embolus, twisted through 90° prolaterally at tip ( Fig. 90 ).

Distribution and natural history ( Fig. 114 ): The natural history of this spider remains unknown. It is claimed to live in ground burrows on the higher slopes of Gunung Rinjani, Lombok Island, Lesser Sunda Islands, Indonesia (G. Albanjari and I. Wayan Suana, pers. comm.).

Remarks: This is the first confirmed record of any theraphosid species on Lombok Island. Roewer (1942, p. 265) listed Phlogiellus inermis ( Ausserer 1871) from Lombok Island, however, the listing is probably erroneous as no description or record of P. i n e r m i s, previous or since, cites this spider from Lombok and the original type locality for the specimens Ausserer examined were from Java and Sumatra only ( Ausserer 1871, p.189).

Figures

FIGURE 63. Lyrognathus lessunda sp. nov., holotype, female in life. Photo: R. C. West.

FIGURES 64 – 70. Lyrognathus lessunda sp. nov. holotype female: 64. Carapace, dorsal view. 65. Eyes, dorsal view. 66. Sternum, labium, maxillae and coxa, ventral view. 67. Labium, ventral view. 68. Left palp, legs I, II, ventral view. 69. Abdomen, legs IV, ventral view. 70. Spermathecae, dorsal view. Scale bar = 10 mm for 64, 66, 69; 5 mm for 68; 2 mm for 65, 67, 70. Photos: S. C. Nunn.

FIGURES 71 – 76. Lyrognathus lessunda sp. nov., holotype female (except: paratype female QM S 74066; 75, 76): 71. Abdomen and legs IV, dorsal view. 72. Left leg IV, retrolateral view. 73. Left leg IV, prolateral view. 74. Left met. and tar. IV, ventral view. 75. Left maxillae, prolateral view. 76. Left maxillary lyra, prolateral view. Scale bar = 10 mm for 71 – 73; 5 mm for 74; 2 mm for 75; 1 mm for 76. Photos: S. C. Nunn.

FIGURES 77 – 80. Lyrognathus lessunda sp. nov. paratype female QM S 74066: 77. Left chelicerae, prolateral view. 78. Left intercheliceral pegs, prolateral view. 79. Left cheliceral strikers, ectal view. 80. Left basomedial cheliceral spines, retrolateral view. Scale bar = 2 mm for 77; 1 mm for 78, 79; 0.5 mm for 80. Photos: S. C. Nunn.

FIGURES 81 – 90. Lyrognathus lessunda sp. nov. paratype male QM S 74069: 81. Habitus, dorsal view. 82. Carapace, dorsal view. 83. Eyes, dorsal view. 84. Sternum, labium, maxillae and coxa, ventral view. 85. Right intercheliceral pegs, prolateral view. 86. Right cheliceral strikers, ectal view. 87. Right maxillae showing lyra, prolateral view. 88. Left bulb, retrolateral view. 89. Left bulb, prolateral view. 90. Left bulb, anterior view. Scale bar = 10 mm for 81; 5 mm for 82, 84; 2 mm for 83, 86, 87; 1 mm for 85, 88 – 90. Photos: S. C. Nunn.

FIGURE 114. Records of Lyrognathus species in Southeast Asia. C. Senescall

FIGURES 20 – 23. Lyrognathus achilles sp. nov., holotype female: 20. Leg IV, dorsal view. 21. Leg IV, prolateral view. 22. Tar. IV, ventral view. 23. Spermathecae, dorsal view. Scale bar = 10 mm for 20, 21; 5 mm for 22; 2 mm for 23. Photos: S. C. Nunn.